Variable stroke pump



March 14, 1950 c. R. SEGLUND 2,500,579

vARIABLEs'rRom PUMP Filed Dec. 31, 1946 zsheets-sheet 1 Mud! 1950 c. R. SEGLUND 2,500,579

VARIABLE STROKE PUMP Filed D90. 31, 1946 2 Sheets-Sheet 2 Izwnfor 70 /6 K9) 70 R. \9 /a 2/ v ,6 i

, while the pump is operating.

Patented Mar. 14, 1950 UNITED STATES PATENT OFFICE x I appumzt zi r ifizzi. 719,574

2 c aim. (01. 74-48) This invention relates to variable stroke pumps, and more particularly to suchpumps having one or more pistons or diaphragms and an adjustable device to vary the length of the stroke.

An object of this invention is to provide a simple, inexpensive and effective mechanism whereby the length of the stroke ,of the pump, and therefore its capacity or flow, may be altered Further objects of this invention will become apparent from the following description when taken in conjunction with the accompanying drawings, the invention being particularly pointed out in the appended claims.

Reference is made to the drawings wherein like numerals of reference apply to the ame parts throughout the several views, and wherein:

Figure 1 is a front elevation, Figure 2 is an end elevation partly in section, Figure 3 is a fragmentary top view, and Figure 4 is a fragmentary front elevation indicating the connections to the pump.

Referring to thedrawings in detail, in Figures land 2, a driving shaft I is rotatably supported in bearings H of housing l2 and has attached to it an eccentric cam I3 operating in the longitudinal bearing slot l4 provided in an eccentric head [5 which is pivotally secured to crosshead 16 by means of bearing pin ll. At the opposite end of eccentric head I5 are provided one or more eccentric rods l8 attached by means of bearing pins l9 and arranged to impart suitable reciprocating motion to diaphragm or piston rod 20 and pump diaphragms or pistons 2|, as shown in Figure 4.

Access to eccentric cam slot II is provided by means of a cap 22 which is shown secured in place by means of screws 23.

Crosshead I6 is slidably supported by the smooth portions of shaft 24. This shaft is rotatably supported in bearing brackets 25 secured to the casing l2 by means of bolts 26 and 21 and is provided with pinned collars 28 and 29 to retain it in proper position. It also has a portion 30 and 3| of its length adjacent each end threaded right and left handed, respectively, for operaupon the pump, it will be seen that the crossfaces of the crosshead l6 and a load is placed head may freely reciprocate along shaft 24 throughoutthis greater distance whenever shaft l0 and eccentric cam I 3 are rotated, and thus the eccentric'head i5, enclosed by the bifurcated lower projection of crosshead l6 pivoting on pin ll, will cause a regulatedmotion to be applied to the eccentric rod IB and eventually to the pump pistons or diaphragms 2|. Thus, the length of the stroke and therefore'the capacity of the pump may be readily altered while in op-- eration without changing the driving speed of the eccentric shaft I ll.

' It is to be understood that various modifications and changes may be made in this invention without departing from the spirit and scope thereof as set forth in the appended claims.

What is claimed is:

1. In a variable stroke mechanism comprising a support, a rotary drive shaft journaled on the support and carrying an eccentric cam, an endwise reciprocable rod disposed transversely of the driven shaft, and a downwardly-extending cam block pivotally connected at the lower portion thereof to the reciprocable rod and having an intermediate vertically-elongated opening forming a cam slot for the eccentric cam traversed by said drive shaft in effective position to engage the cam with the sides of the cam slot, a pair of abutment means spaced apart on the support and means for adjusting the relative distance between the two abutment means, the improvements which include a slideway on said support between said two abutment means disposed transversely of the drive shaft, a slidable block reciprocable and slidable on said slideway from one abutment means to the other, and a depending portion upon the slidable block pivotally connected to the upper end of said cam block to allow the latter to swing from said slidable block about a pivot axis parallel to said drive shaft in a direction from side to side relative to said slidable block to reciprocate said reciprocable rod during rotation of said drive shaft with consequent reciprocation of said slidable block along said slideway between the two abutment means.

2. In a variable stroke mechanism comprising a support, a rotary drive shaft journaled on the support and carrying an eccentric cam, an endwise reciprocable rod disposed transversely of the driven shaft, and a downwardly-extending cam block pivotally connected at the lower portion thereof to the reciprocable rod and having an intermediate vertically-elongated opening forming a cam slot for the eccentric cam traversed by said I drive shaft in effective cam with the sides of the cam slot, 0. pair of means for adjusting the relative distance be- 1 tween the two abutment means, the improvements which include elongated guide means ineluding a second shaft rotatably mounted on said 1 support between the two abutment means, the second shaft having oppositely-threaded ends and an intermediate smooth portion, a thumb wheel fixed on one end of said second shaft for rotating 1 the same at will, a pair of internally-threaded 1 simultaneously-adjustable nuts mounted on the threaded ends of said second shaft and forming said two abutment means. a slidable block position to engage the mounted on the second shaft and slidable upon i the intermediate smooth portion thereof between 1 said adjustable nuts from one nut to the other in a direction transverse to that of the axis of said drive shaft, depending lug means integral j upon the lower portion of said slidable block, corresponding upwardly-extending lug means on 3 the upper end of said cam block, and a pivot pin extending through both lug means in substan- 1 tie] parallelism to said drive shaft and transversely of said second shaft to allow the cam block to swing from said slide block about a pivot axis parallel to said drive shaft from side to side relative to said slidable block in such fashion as to reciprocate said reciprocable rod during rotation of said drive shaft with consequent reciprocation of said slidable block along said smooth portion of said second shaft between the two adjusting nuts.

CARL R. SEGLUND.

REFERENCES CITED 10 The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 619,824 Fetzer Feb. 21, 1899 762,055 Hibbard June '7, 1904 797,742 MCCOId Aug. 22, 1905 1,006,831 Dallemague Oct. 24, 1911 1,321,278 Bellam Nov. 11, 1919 1,500,065 Ferguson July 1, 1924 1,642,259 Morse Sept. 13, 1927 2,147,989 Puurmann Feb. 21, 1939 2 FOREIGN PATENTS Number Country Date 12,004 Great Britain of 1901 742,242 France Dec. 27, 1932 

